50 to 60 ft.
25 to 30 ft.
USDA zones 3-9
hardy to 8,000 ft.
Green ash is a large, native, deciduous tree with upright branches, spreading form and irregular crown. Shiny medium green leaves turn yellow to orange in the fall. Seeds are paper brown samaras.
Green ash was once a highly recommended tree. Due to the presence of the emerald ash borer in Colorado, tree care professionals are no longer recommending ash trees be planted in Colorado.
'Marshal' is a seedless cultivar with darker green leaves tuning yellow in fall, and bark that creates a diamond pattern up the trunk. 'Cimmaron' is also seedless with a more upright and columnar shape, glossy green leaves turn to reddish purple in the fall.
This is a widely planted tree in the Colorado Springs area, including the Xeriscape Garden where they have proven to be good shade trees.
For many years, 'Marshall,' 'Cimmaron,' or other seedless cultivars were recommended for new plantings to eliminate the annoyance of self seeding. A mature seeded ash can produce thousands of seedlings on an annual basis.
Prune when young to achieve a structurally sound tree. For existing trees, protect them from emerald ash borer once the insect is found within a 50 mile radius. It is currently limited to the Boulder/Denver area.